mercruiser 888 heads

[jmoorepghpa]

Head on the old 888 cracked. The 888 used 351w heads drilled with smaller head bolt holes to fit 302. I would assume 302 heads like the later e7te's will work with the factory mercruiser intake. Anyone have a simple intake/carb combo that will boost up the hp a little. I see some in the edelbrock marine section and was wondering if anyone has any advice. I'm keeping the stock cam and short block. If I could get maybe 220 hp up from the stock 190 I would be ok with that. Our boat is usually loaded and a little extra umph would be nice.

 

[qaztwo]

Re: mercruiser 888 heads

the 351 head bolts are 1/2 302 7/16( I think), the head wouldn't be drilled. you would need conversion bolts.

The older heads, DOOE, have the larger valves.

 

[Boomyal]

Re: mercruiser 888 heads

the 351 head bolts are 1/2 302 7/16( I think),

You thought correctly qaztwo. The variance is that the 888 heads were 351's factory heads, drilled with the 7/16 302 head bolt holes. You will never find those head numbers, in the automotive salvage market, with other than the 1/2" 351 holes. You would have to use the adaptor washers that are available from Summit racing.

You are also correct in that the early heads had the bigger valves. ie, earlier than those Ford motors were used with the Mercs and OMC's. As the relatively low rpm marine motors don't require high rpm air flows, they really won't make any difference.